7. 3rd generation mobile communication: UMTS · lectures of Mobile Communication/Computer Networks...

1Copyright © 2008 Prof. Dr. Peter Martini, Dr. Matthias Frank, Institute of CS IV, University of Bonn

Mobile CommunicationChapter 7.

7. 3rd generation mobile communication: UMTS

7.1. Overview of UMTS

7.2. UMTS Architecture

7.3. WCDMA Principles

7.4. UTRAN Architecture

7.5. Macro-diversity & Handover

Annex (in German): Results Frequency Auction UMTS

7.6. Breathing cells & Power Control

7.7. Enhancements: EDGE & HSDPA

7.8. IMS – IP Multimedia Subsystem

7.9. Outlook: Future generations of mobile communication



Acknowledgements

Several slides of this subsection are taken from material of guest lecturesthat have been performed by Nokia Research Center Bochum in earlierlectures of Mobile Communication/Computer Networks II (Rechnernetze II)in summer terms 2001 – 2005.

Credits go to• Dr. Paul James• Oliver Lüert• Ulrich Müller

The slides are marked in the lower left corner.

Once again:

Several slides in this chapter are very much based on Jochen Schiller’s work.The copyright of these slides - marked “JS” in the upper right corner - is with Jochen Schiller.

Further information on Prof. Schiller’s work, including his excellent books, is available at http://www.jochenschiller.de



7.1. UMTS - Universal Mobile Telecommunication System

3GPP - Third Generation Partnership Project(founded in 1997 by ETSI)

Global cooperation for 3G mobile communication

UMTS – European contribution to third generation mobile communication (3G)driven by ETSI, Technical Sub-Committee (STC) SMG 5 (Special Mobile Group)

Online-Info:

www.etsi.org

www.3gpp.org

www.umts-forum.org

www.itu.int

3GPP foundation members:

• ARIB Association of Radio Industries and Businesses, Japan• ETSI European Telecommunications Standards Institute, Europe• Committee T1 Standards Committee T1 Telecommunications, USA• TTA Telecommunications Technology Association, South Korea• TTC Telecommunication Technology Committee, Japan

UMTS Forum in 3GPP since end of 1998

UMTS is part of the family of IMT-2000: ITU International Mobile Communications at 2000 MHzWorld-wide coordination of 3G activities.



UMTS/IMT 2000 is universal

Zone 4:

SatelliteZone 3:S b b

Zone 2:

Zone 1:In building

Macro cellPico cellMicro cellWorld cell

2Gs: Satellitenetworks

public mobile &fixed networks

privat residential &fixed networks (A

bb.q

uelle

: Rep

ort N

o. 6

from

the

UM

TS

For

um,

ww

w.u

mts

-for

um.o

rg)

• Global System: national terrestrial components and global (world-wide) satellite technology• Multi-mode and multi-band technology includes systems of second generation (2G, 2.5G)

• First goal: Personal communication, roaming without limitations:- private network(s)- Pico (building) or Micro (regional) public cellular networks- Macro/Wide Area Network- Global world-wide satellite technology

• Second goal: Consistent “Look and Feel” independent of location and network- “Virtual Home Environment” VHE



UMTS and IMT-2000

• Proposals for IMT-2000 (International Mobile Telecommunications)– UWC-136, cdma2000, WP-CDMA

– UMTS (Universal Mobile Telecommunications System) from ETSI

• UMTS– UTRA (was: UMTS, now: Universal Terrestrial Radio Access)

– enhancements of GSM• EDGE (Enhanced Data rates for GSM Evolution): GSM up to 384 kbit/s

• CAMEL (Customized Application for Mobile Enhanced Logic)

• VHE (virtual Home Environment)

– fits into GMM (Global Multimedia Mobility) initiative from ETSI

– requirements• min. 144 kbit/s rural (goal: 384 kbit/s)

• min. 384 kbit/s suburban (goal: 512 kbit/s)

• up to 2 Mbit/s urban

JS



Frequencies for IMT-2000

IMT-2000

1850 1900 1950 2000 2050 2100 2150 2200 MHz

MSS↑

ITU allocation(WRC 1992) IMT-2000

MSS↓

Europe

China

Japan

NorthAmerica

UTRAFDD ↑

UTRAFDD ↓

TDD

TDD

MSS↑

MSS↓

DECT

GSM1800

1850 1900 1950 2000 2050 2100 2150 2200 MHz

IMT-2000MSS

↑ IMT-2000MSS

↓GSM1800

cdma2000W-CDMA

MSS↓

MSS↓

MSS↑

MSS↑

cdma2000W-CDMA

PHS

PCS rsv.

JS

MSS = mobile satellite services



Duplex with UMTS ?

Duplex – separation of uplink and downlink

Both concepts are used:• FDD: Frequency Division Duplex, use pair of frequencies/spectrum in parallel (same as GSM)• TDD: Time Division Duplex, unpaired frequencies/spectrum, time division of Downlink/Uplink

1850 1900 1950 2000 2050 2100 2150 2200 2250 MHz

1850 1900 1950 2000 2050 2100 2150 2200 2250 MHz

NorthAmerica

MSS Reserve

Europe UMTSGSM 1800 DECT MSS

1880

1980

JapanKorea (w/o PHS)

MSSIMT 2000PHS MSSIMT 2000

2160

1893 1919

ITU Allocations

1885

IMT 2000

2010 2110 2170

China MSSIMT 2000IMT 2000

IMT 2000

MSSUMTS

MSS

1990

A D B E F A B CMSS

MDS

WLL WLL

2025 22001900

MSS MSS

GSM1800

D FEB B

PCSC

MDS =Multipoint Service/

Mobile Data Service

MSS =Mobile Satellite

Services

(Abb.quelle: Report No. 6 from the UMTS Forum, www.umts-forum.org)

Paired frequency band for FDD

Unpaired frequency band, for TDD



IMT-2000 family

IMT-DS(Direct Spread)

UTRA FDD(W-CDMA)

3GPP

IMT-TC(Time Code)UTRA TDD(TD-CDMA);TD-SCDMA

3GPP

IMT-MC(Multi Carrier)

cdma2000

3GPP2

IMT-SC(Single Carrier)

UWC-136(EDGE)

UWCC/3GPP

IMT-FT(Freq. Time)

DECT

ETSI

GSM(MAP)

ANSI-41(IS-634)

IP-NetworkIMT-2000Core NetworkITU-T

IMT-2000Radio AccessITU-R

Interface for Internetworking

Flexible assignment of Core Network and Radio Access

Initial UMTS(R99 w/ FDD)

JS



GSM and UMTS Releases

Stage 1 freezeMar. 2008

(stage 2,3 open)8.x.yRel-8Release 8Phase 2+ Release 8

Stage 3 freezeDec. 2007

7.x.yRel-7Release 7Phase 2+ Release 7

19923.x.yPh1-Phase 1

19954.x.yPh2-Phase 2

early 19975.x.yR96-Phase 2+ Release 1996



8.x.y-Phase 2+ Release 1999March 2000

3.x.yR99

Release 1999-

9.x.y-Phase 2+ Release 2000Renaming…

4.x.yR00

Release 2000-

March 20014.x.yRel-4Release 4Phase 2+ Release 4

March - June 20025.x.yRel-5Release 5Phase 2+ Release 5

December 2004 -March 2005

6.x.yRel-6Release 6Phase 2+ Release 6

Freeze date(indicative only)

Spec versionnumber

Abbreviatedname

3G ReleaseGSM/EDGE Release

JS



7.2. UMTS Architecture (Release 99 used here!)

UTRANUE CN

IuUu

• UTRAN (UTRA Network)– Cell level mobility

– Radio Network Subsystem (RNS)

– Encapsulation of all radio specific tasks

• UE (User Equipment)

• CN (Core Network)– Inter system handover

– Location management if there is no dedicated connection between UE and UTRAN

JS



UMTS architecture (2)

GSM + WCDMA

Co-sited GSM + WCDMA

GSM / WCDMAmobile

WCDMAmobile

WCDMA

WCDMABTS WCDMA

BSC

GGSN

SGSN

GPRS

Internet(TCP/IP)Internet(TCP/IP)

IN

GSM mobile

BSS

NSS

Landline Ntw(PSTN/ISDN)Landline Ntw(PSTN/ISDN)

SIM card

BSC

MSC

HLR

BTS

Multi-mode/Multi-band using several radio access network technologies.



UMTS domains and interfaces I

• User Equipment Domain– Assigned to a single user in order to access UMTS services

• Infrastructure Domain– Shared among all users

– Offers UMTS services to all accepted users

USIMDomain

MobileEquipment

Domain

AccessNetworkDomain

ServingNetworkDomain

TransitNetworkDomain

HomeNetworkDomain

Cu Uu Iu

User Equipment Domain

Zu

Yu

Core Network Domain

Infrastructure Domain

JS



UMTS domains and interfaces II

• Universal Subscriber Identity Module (USIM)– Functions for encryption and authentication of users

– Located on a SIM inserted into a mobile device

• Mobile Equipment Domain– Functions for radio transmission

– User interface for establishing/maintaining end-to-end connections

• Access Network Domain– Access network dependent functions

• Core Network Domain– Access network independent functions

– Serving Network Domain• Network currently responsible for communication

– Home Network Domain• Location and access network independent functions

JS



7.3. WCDMA Principle(I) : Spread Spectrum

• WCDMA is a spread spectrum transmission where the users signal is broadcast over the entire frequency spectrum along with signals from other users.

• This is similar to a situation at a party where everyone is talking simultaneously. The brain picks out the conversation listened to from all of the other simultaneous conversations.

• WCDMA works in a similar way such the transmission/reception hardware can extract one particular transmission from all the others by 'tuning' the receiver to a particular transmission using a special coding technique.

• This is simultaneously performed for all of the transmissions in a cell

(Slide source: Nokia/NRC guest lectures Mobile Communication 2001-2005)

WCDMA – Wideband CDMA (Code Division Multiple Access)



WCDMA Principle (II) : Spread Spectrum

HI

HI

Operation

HI

HI

HI

HIHI

HI

HI

HI

HI

HIHI

HIHI

HI

HI

HI

HI

HI

HI

HI

HI

HI

HI

HI HIHI HI

HI

HI

HI

HIHI


HI



WCDMA Principle (III) : Spread Spectrum

HI

HI

Operation

HI

HI

HI

HIHI

HI

HI

HI

HI

HIHI

HIHI

HI

HI

HI

HI

HI

HI

HI

HI

HI

HI

HI HIHI HI

HI

HI

HI

HIHI


HI



Code division = different languages




Multiple Access with CDMACDMA - Code Division Multiple Access

Fixed channel size with GSM (combination of FDMA and TDMA) : Division of frequencies, each channel division into cyclic time-slots

Three transmissions using FDMATime

Frequency

Bandwidth ofsignal

Three transmissions using CDMA

Frequency

Time

Signal 3 (Code 3)

Signal 1 (Code 1)

Idea of CDMA:• uses the whole bandwidth all the time• channels are separated by “codes”• a radio signal (e.g. voice data) with a narrow band will be transmitted using amultiple of the necessary bandwidth (signal spreading)

• broadband signals of several channels will be added on the medium “air”

• different channels use “orthogonal” codes• the receiver is able to filter out a specific channel with its code

=> cf. subsection3. Wireless Communication Basics



Coding and Decoding with CDMA

PN1

PN2

PN3

Data 1

Data 2

Data 3

+

Pseudo Noise (PN) Code for „signal spreading“

PN1

PN2

PN3

„Channel“

Narrow banduser signal

„Spreading“ withcode sequence(multiplication)

Multiplication ofnecessarybandwidth

Superposition ofbroadband signalsin the sharedmedium „air“

AttenuationInterference

Secondmultiplicationwith PN-codesequence(filter)

„Comparator“decides between0 and 1(original usersignal)

=> cf. subsection3. Wireless Communication Basics



Spreading and scrambling of user data

• Constant chipping rate of 3.84 Mchip/s

• Different user data rates supported via different spreading factors– higher data rate: less chips per bit and vice versa

• User separation via unique, quasi orthogonal scrambling codes– users are not separated via orthogonal spreading codes

– much simpler management of codes: each station can use the same orthogonal spreading codes

– precise synchronisation not necessary as the scrambling codes stay quasi-orthogonal

data1 data2 data3

scramblingcode1

spr.code3

spr.code2

spr.code1

data4 data5

scramblingcode2

spr.code4

spr.code1

sender1 sender2

JS



OVSF coding

1

1,1

1,-1

1,1,1,1

1,1,-1,-1

X

X,X

X,-X 1,-1,1,-1

1,-1,-1,1

1,-1,-1,1,1,-1,-1,1

1,-1,-1,1,-1,1,1,-1

1,-1,1,-1,1,-1,1,-1

1,-1,1,-1,-1,1,-1,1

1,1,-1,-1,1,1,-1,-1

1,1,-1,-1,-1,-1,1,1

1,1,1,1,1,1,1,1

1,1,1,1,-1,-1,-1,-1

SF=1 SF=2 SF=4 SF=8

SF=n SF=2n

...

...

...

...

JS

OVSF = Orthogonal Variable Spreading Factor (3G UMTS coding scheme)



Channelization Codes




Scrambling Codes




Codes in Downlink


Code x can be any codewith same spreading factor



Codes in Uplink


Code x can be any code



Overview Channelization vs. Scrambling




7.4. UTRAN Architecture

• UTRAN comprisesseveral RNSs

• Node B can support FDD or TDD or both

• RNC is responsible forhandover decisionsrequiring signalingto theUE

• Cell offers FDD or TDD

RNC: Radio Network Controller

RNS: Radio Network SubsystemNode B

Node B

RNC

Iub

Node B

UE1

RNS

CN

Node B

Node B

RNC

Iub

Node B

RNS

Iur

Node B

UE2

UE3

Iu

JS(UTRAN = Universal Terrestrial Radio Access Network)



UTRAN functions

• Admission control• Congestion control• System information broadcasting• Radio channel encryption• Handover• SRNS moving (Serving RNS)• Radio network configuration• Channel quality measurements• Macro diversity• Radio carrier control• Radio resource control• Data transmission over the radio interface• Outer loop power control (FDD and TDD)• Channel coding• Access control

JS



Core network: protocols

MSC

RNS

SGSN GGSN

GMSC

HLR

VLR

RNS

Layer 1: PDH, SDH, SONET

Layer 2: ATM

Layer 3: IPGPRS backbone (IP)

SS 7

GSM-CSbackbone

PSTN/ISDN

PDN (X.25),Internet (IP)

UTRAN CN

JS



Core network: architecture

BTS

Node B

BSC

Abis

BTS

BSS

MSC

Node B

Node B

RNC

Iub

Node BRNS

Node BSGSN GGSN

GMSC

HLR

VLR

IuPS

IuCS

Iu

CN

EIR

GnGi

PSTN

AuC

GR

JS



Core network

• The Core Network (CN) and thus the Interface Iu, too, are separated into two logical domains:

• Circuit Switched Domain (CSD)– Circuit switched service incl. signaling

– Resource reservation at connection setup

– GSM components (MSC, GMSC, VLR)

– IuCS

• Packet Switched Domain (PSD)– GPRS components (SGSN, GGSN)

– IuPS

• Release 99 uses the GSM/GPRS network and adds a new radio access!– Helps to save a lot of money …

– Much faster deployment

– Not as flexible as newer releases (5, 6)

JS



UMTS protocol stacks (user plane)

apps. &protocols

MAC

radio

MAC

radio

RLC SAR

Uu IuCSUE UTRAN 3GMSC

RLC

AAL2

ATM

AAL2

ATM

SAR

apps. &protocols

MAC

radio

MAC

radio

PDCP GTP

Uu IuPSUE UTRAN 3GSGSN

RLC

AAL5

ATM

AAL5

ATM

UDP/IP

PDCP

RLC UDP/IP UDP/IP

Gn

GTP GTP

L2

L1

UDP/IP

L2

L1

GTP

3GGGSN

IP, PPP,…

IP, PPP,…

IP tunnel

Circuitswitched

Packetswitched

JS



7.5. Support of mobility: macro diversity

• Multicasting of data via several physical channels– Enables soft handover

– FDD mode only

• Uplink– simultaneous reception of UE

data at several Node Bs

– Reconstruction of data at Node B, SRNC or DRNC

• Downlink– Simultaneous transmission of

data via different cells

– Different spreading codes in different cells

CNNode B RNC

Node BUE

JS



WCDMA Principle: Macro-diversity

HI

HIMacro-diversity




WCDMA Principle: Macro-diversity (2)

NodeB

NodeB

NodeB

RNCUE

Macro-diversity

UTRAN




Support of mobility: handover

• From and to other systems (e.g., UMTS to GSM)– This is a must as UMTS coverage will be poor in the beginning

• RNS controlling the connection is called SRNS (Serving RNS)

• RNS offering additional resources (e.g., for soft handover) is called Drift RNS (DRNS)

• End-to-end connections between UE and CN only via Iu at the SRNS– Change of SRNS requires change of Iu– Initiated by the SRNS

– Controlled by the RNC and CN

SRNC

UE

DRNC

Iur

CN

Iu

Node BIub

Node BIub

JS



Example handover types in UMTS/GSM

RNC1

UE1

RNC2

Iur

3G MSC1

Iu

Node B1

IubNode B2

Node B3 3G MSC2

BSCBTS 2G MSC3

AAbis

UE2

UE3

UE4

JS



Macro-diversity Situations: Handover 1/3

VLRC

RNC

BTSBTS

VLRC

RNC

BTSBTS

VLRMSC

MSC/VLR

VLRMSC

MSC/VLR

Radio Link addition triggered Resulting Connection

VLRC

RNC

BTSBTS

VLRC

RNC

BTSBTS





VLRC

RNC

BTSBTS

VLRC

RNC

BTSBTS

VLRMSC

MSC/VLR

VLRMSC

MSC/VLR


VLRC

RNC

BTSBTS

VLRC

RNC

BTSBTS





VLRC

RNC

BTSBTS

VLRC

RNC

BTSBTS

VLRMSC

MSC/VLR

VLRMSC

MSC/VLR


VLRC

RNC

BTSBTS

VLRC

RNC

BTSBTS




7.6. Breathing Cells

• GSM– Mobile device gets exclusive signal from the base station – Number of devices in a cell does not influence cell size

• UMTS– Cell size is closely correlated to the cell capacity– Signal-to-noise ratio determines cell capacity– Noise is generated by interference from

• other cells• other users of the same cell

– Interference increases noise level– Devices at the edge of a cell cannot further increase their

output power (max. power limit) and thus drop out of the cell no more communication possible

– Limitation of the max. number of users within a cell required

– Cell breathing complicates network planning

JS



Breathing Cells: Example JS



WCDMA Principle: Power Control

HI

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Power Control

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HIHI

HIHI

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HIHIHI

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Power Control: Motivation




WCDMA Principle: Power Control (2)

RNC

Open Loop Power Control (Initial Access)

Closed Loop Power Control

Outer Loop Power Control

MS BTS

Power Control (PC) Loops in WCDMA




Closed-loop vs. open-loop




7.7. Some current/further enhancements

• GSM– EMS/MMS

• EMS: 760 characters possible by chaining SMS, animated icons, ring tones, was soon replaced by MMS (or simply skipped)

• MMS: transmission of images, video clips, audio

– EDGE (Enhanced Data Rates for Global [was: GSM] Evolution)• 8-PSK instead of GMSK, up to 384 kbit/s

• new modulation and coding schemes for GPRS EGPRS– MCS-1 to MCS-4 uses GMSK at rates 8.8/11.2/14.8/17.6 kbit/s

– MCS-5 to MCS-9 uses 8-PSK at rates 22.4/29.6/44.8/54.4/59.2 kbit/s

• UMTS– HSDPA (High-Speed Downlink Packet Access)

• initially up to 10 Mbit/s for the downlink, later on 20 Mbit/s using MIMO-(Multiple Input Multiple Output-) antennas

• uses 16-QAM instead of QPSK

JS



Example: EDGE coverage for T-Mobile Germany

EDGE is availablein the completeGSM networkof T-Mobile.

Source: http://www.t-mobile.de/URL http://www.t-mobile.de/business/netzabdeckung/0,12565,14540-_,00.html(used on 18.06.2008)



HSDPA




Example: HSDPA coverage for T-Mobile Germany

HSDPA is availablein the completeUMTS networkof T-Mobile.

(UMTS available in mainmetropolitan areas)

Source: http://www.t-mobile.de/URL http://www.t-mobile.de/business/funkversorgung/inland(used on 18.06.2008)



7.8. IP Multimedia Subsystem (IMS)

IMS* represents an overlay network on top of cellular networks and provides an all IP service delivery environment for mobile multimedia service provision.

* IMS is the “IP Multimedia System”, standardised by the 3rd Generation Partnership Projekt (3GPP), http://www.3gpp.org

Why do we Need an IMS?

• IMS builds on IETF protocols, to create a robust and complete multimedia system

• IMS defines common interfaces to adopt new and integrated application services

• IMS enhancements and operational profiles provide support for operator control, charging and billing, and security

• IMS provides QoS, single sign-on, subscription, presence, and location

• SIP, and SDP for Session Control• DIAMETER for accounting• RTP, RTCP for multimedia data transport• COPS for policy provisioning• plus many others

• SIP, and SDP for Session Control• DIAMETER for accounting• RTP, RTCP for multimedia data transport• COPS for policy provisioning• plus many others IMS is designed for IPv6, but

support for IPv4 has been added in Version 6 of IMS



IMS – IP Multimedia Subsystem

Source: IEEE Communications Magazine, August 2006, pp. 75-81

The IMS “service platform” is/was designed by 3GPP (http://www.3gpp.org) to assist and control (multimedia) sessions established between peers. The peers willing to involve IMS in their sessions must us some of the IMS nodes as proxies for their session signaling.

CSCF: Call Service Control FunctionP-CSCF: Proxy-CSCFS-CSCF: Serving-CSCFSIP: Session Initiation Protocol



SIPPROXY

IMS Conceptional Architecture

SIP Session Control

Function

SIP

Subscription Server

Function

DIAMETER

Media Gateway Function

RTP SIP

Signaling Gateway Function

SIP

Media Server

Function

SIPSIP

RTP

SIP Application Server

Function

DIAMETER

SIP Session Control

Function



7.9. Mobile Future: 3.5G … 3.9G … 4G …

http://www.teltarif.de/ News 10.06.2005http://www.teltarif.de/arch/2005/kw23/s17412.html

3.5 generation of mobile communication:

• HSDPA/HSUPA (D = downlink, U = uplink) extension to UMTS• Downlink up to 14.4 Mbit/s, Uplink up to 5.7 Mbit/s

3.9 generation of mobile communication:

• UTRAN LTE ("Universal Terrestrial Radio Access Network Long Term Evolution")• also: “Super 3G”• Downlink up to 100 Mbit/s, Uplink up to 50 Mbit/s• 3GPP 3.9G specification approved 2nd half of 2007

4th generation of mobile communication:

• All-IP based• NTT DoCoMO (Japan) testing since 1998• data transfer rates 100 Mbit/s up to 300 Mbit/s



Future statement as of June 2008More on http://www.computerzeitung.de/articles/tage_von_wimax_und_wlan_gezaehlt:/2008025/31545147_ha_CZ.html?thes=or http://www.computerzeitung.de/kn31539662

“WLAN and WiMAX’s days are numbered”

Next generation technologies of mobile communicationwill make technologies like WLAN, WiMAX, … obsolete:

• HSDPA+• LTE

using• MIMO (multiple input multiple output) antennas• OFDM

(Qualcomm CEO Paul Jacobs, June 2008)



Annex: Ergebnis Frequenzvergabe für UMTS – FDD (1)

UMTS-Versteigerung Deutschland14. Tag = 17.08.2000 (bis Runde 173)Rundenergebnis des Abschnitts 1 (FDD Frequenzblöcke)

(in German language)



Ergebnis Frequenzvergabe für UMTS – FDD (2)

UMTS-Versteigerung Deutschland14. Tag = 17.08.2000 (bis Runde 173)Stand der Lizenzvergabe (FDD Frequenzblöcke)

UTRA-FDD:

Uplink 1920-1980 MHz

Downlink 2110-2170 MHz

Duplexabstand 190 MHz

12 Kanäle zu je 5 MHz



Ergebnis Frequenzvergabe für UMTS – TDD

UMTS-Versteigerung Deutschland1. Tag = 18.08.2000 (bis Runde 9)Endergebnis Abschnitt 2 (TDD Frequenzblöcke)

Ziel gemäß Lizensierung:

Abdeckung: 25% in der Bevölkerung bis 12/2003,50% bis 12/2005

UTRA-TDD:

1900-1920 MHz,

2010-2025 MHz;

je 5 MHz Kanäle

7. 3rd generation mobile communication: UMTS · lectures of Mobile Communication/Computer Networks...

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